There are lots of places around St Louis for quality instruction. I would guess most places have a Women's only type beginner class. I know that The Range in Ballwin has one, Sharpshooters has one, Ultimate Defense has one, and so on. You could also have her check into The Well Armed Woman. They are a national organization that has local chapters around the country. There are probably 4 or 5 chapters in the St Louis area. Now this is not a substitute for a class, but it is basically a group of women that get together once a month for some sort of class. The class could be something along the lines of basic shooting stuff, or it could be something woman specific. After the class time, whom ever wants to shoot goes to the range and shoots. You will have women in the class that range in experience from None to Competitive Shooters. My wife was a member of a chapter down at Top Gun and loved it. She has been waiting for our chapter to get going in West County at The Range, which will hopefully be soon.
Phil